Manifold record material and process for making it



April 10, 1951 B. K. GREEN ET AL I 2,548,366

MANIFOLD RECORD MATERIAL AND PROCESS FOR MAKING IT Filed July 31, 1948 [MANIFOLD RECORD MATERIAQ PAPER OR OTHER 5%? MATERIAL FRONT SURFACE COATED PROFUSELY WITH MINUTE souo COLOR-REAGTANT ADSORB- ENT PARTICLES HELD IN A BINDER FILM.

REAR SURFACE COATED WITH RUPTURABLE FILM PROFUSELY PROVIDED WITH EN- TRAPPED LIQUID DROPLETS OF ADSORBATE MATERIAL CONTAIN- INC A SUBSTANCE GIVING A DIS- TINOTIVE COLOR WHEN ADSORBED BY THE PARTICLES ON THE FRONT SURFACE OF ANOTHER UNDERLYING SHEET HAVING A FRONT ADSORB- ENT COATING.

Inventors BARRETT K. GREEN 8 ROBERT W. SANDBERG THEIR Gttorneg Patented Apr. 10, 1951 MANIFOLD RECORD MATERIAL AND PROCESS FOR MAKING IT Barrett K. Green and Robert W. Sandberg, Dayton, Ohio, assignors to The National Cash Register Company, Dayton, Ohio, a. corporation of Maryland Application July 31, 1948, Serial N 0. 41,756

2.7 Claims. 1

This invention relates to manifold record material and to a process for making it, and more particularly pertains to such record material which acts both as a receiving sheet and a transferring sheet and, hence, is suitable for use in a stack or pile wherein an original entry made on the top sheet by impact or pressure is reproduced on the top surface of each under sheet without the necessity of using interleaved transfer sheets.

It'is', of course, recognized that heretofore it has been possible transfer from the back of an entry receiving sheet to an under sheet, without the use of interleaved transfer sheets like carbon paper, by simply'coating the back of thereceiving sheet with a carbon transfer composition or the equivalent. Such a sheet coated on the back with ordinary carbon transfer composition smudges and dirties the under sheets or the operators hands. Moreover, being coated with colored marking materials, ordinarily-of dark appearance, such sheets are not attractive.

The novel transfer sheet which is the subject of this invention is smudge-proof and pleasing in appearance, being white on both sides or white on the receiving side and a pleasing color on the back side, as the material transferred to theunder sheet causes color therein only by reason of a color reaction between the transferred material and the sensitized receiving surface, producing a distinctively colored mark on the receiving surface without changing the appearance of the back of the sheet from which such transfer is, made. The receiving surfaceis such that, although it is sensitized, it may be used as the surfaceon whic the original entryis made by writingtyping or printing. A 3 g The color reaction which causes the distinctively colored marks to appear at points of pressure on the under sheets is of the type known as an adsorption color reaction whereina color reactant material changes color when adsorbed on a'suitable adsorbent material, without the presenceof any ionizingmedium. Y

The reactant material which changes color is an electron donor aromatic organic compound having a double bond system which convertible to a more highly polarized conjugated form upon taking part in an electron acceptor-donor surface chemical reaction, giving it a distinctivelcolor, and the adsorbent material is an inorganic sub} stance which is an acid rel'ativto the organic" compound so as to be an electron acceptorfwhen in adsorption contact therewith. The adsorbent material is in fine particle form to provide a large adsorbent surface area pernnit area of the rec'- 0rd material, and the organic compound is carried ina fluid so it is more readily mobile to make adsorption contact with the adsorbent.

In our oo-pending application for United States Letters Patent Serial No. 38,547, filed by July 13, 1948, there is disclosed a pressure sensitive record material producing color by the same type of color reaction except the record material disclosed therein was coated on one side only with the two color reactants superimposed in proximity but insulated from each other by a pressure rupturable film. Any pressure or below on such a sheet produces color.

In the present invention the individual sheet is immune to any pressure or impact, it being necessary to bring two such sheets into superimposed relation where the back surface of one sheet rests on the front surface of another sheet of thesame material before a color reaction can be caused by pressure. I

The color reactant on the sensitized receiving surface is the inorganic reactant in small solid particle form profusely dispersed in a binder coating so that the particles are available for contact by the color reactant droplets transferred from the back of the superimposed sheet by pressure. The transfer coating is a rupturable film having profusely dispersed therein small droplets of an inert oily solvent in which the organic color reactant is dissolved, said droplets being expelled locally at points of pressure.

Therefore, it is an object of this invention to provide a sheet of record material which has on a front receiving surface a coating containing small solid particles of a first color reactant material and which has on the rear surface a pressure rupturable coating which has profusely dispersed therein minute liquid droplets containing a second color reactant which produces a distinctive color when in contact with the first color reactant, the droplets being extrudable locally from the coating on pressure being applied so as to come in contact with the receiving front surface of an. underlying sheet of the same kind, there to produce a distinctively colored mark.

Another object of the invention is to provide a process for making such record material.

Further objects and objects relating to details and economies of production will definitely appear from the detailed description to follow. The objects of this invention have been attained by the several embodiments thereof described in detail in the following specifications. The invention is clearly defined and pointed out in the appended claims. I

The sensitized receiving surface of the sheet contains as the active ingredienta materialupon which the active ingredient of the liquid drops lets received from the bottom of anoverlying sheet may be adsorbed, the adsorbate in the liq-- uid and the adsorbent being selected so as to produce a color upon adsorption taking place.

Among the most satisfactory adsorbents from an economic and functional standpoint are at tapulgite, sodium aluminum silicate zeolite material in which the sodium base exchange cations may be replaced by cations of nickel, copper, iron, Zinc, mercury, barium, lead, cadmium or potassium, if desired, to give equivalent or better color reactions, attapulgite in which the natural base exchange cations have been replaced by any of jthe above mentioned replacement cations or hydrogen, halloy'site and magnesium trisilicate. Mixtures of these adsorbents may be used with good results. All of these materials may be applied'to the sheet by use of a white or colorless binder to give a white surface which will receive inkor' other marking fluid as well as being adsorptive with respect to the adsorbate in the liquid received from the rear surface coating of an overlying sheet. Thus, the novel manifold sheet may beused as a top sheet as well as an intermediate or bottom sheet of a stack.

The color reactant adsorbate carried in the rear surface film of the novel manifold sheet is present therein dissolved in minute droplets of an oily, non-evaporable, inert liquid medium, preferably a chlorinated diphenyl and may consist of one or more color reactants such as crystal violet lactone, which is 3.3 bis(p-dimethylaminophenyl)-6+dimethylamino phthalide, having the structure I KQ aM malachite green lactone, which is 3,3 bis(p-dimethylaminophenyl) phthalide, having the structetrachloro malachite green-lactone which is 3,3 bis (p-dimethylaminophenyl) -4,5,6,7 tetrachloro phthalide, having the structure engine on t1 3,3 bis(pediethylaininophenyl) -6-dimethylamino phthalide, having the structure C I V ii-iL Qh NOMCHa):

The adsorbate color reactant dissolved in the inertoily liquid medium is-heldas minute droplets profusely dispersed in a solid pressurerupturable film,-- preferably of gelatin derived from anemulsion in which gelatin in water forms the continuous phase, which is dryableto form the film, and in which the oily solution forms the'discontinuous phase. 7

The adsorbent may be applied to the sheet by the use of an ordinary paper coating starchbinder.

Thishanifold sheet is animprovement on the manifold sheet disclosed in Barrett K. Greens United-StatesPatent No. 2,374,862 issued on May 1, 1945, which was useful only as an overlying sheet and which wasnot sensitized toreceivedata from an overlying sheet; The present improvement provides a recordmaterial sheet having the dual featuresof beingsensitized to receive data from an overlying sheet and of transferring it to an under sheet. The novel manifold sheet is smudge-proof on both sides and is not subject to discoloration byhandling as the reactants are on opposite sides of the sheet.

In the following examples, there will be described embodiments of this invention by which the objects of theinvention have been successfully attained.

Example 1.-The following embodiment of this invention constitutes the best mode of applying the principles thereof, as contemplated up to the present time andmay be considered the preferred embodiment. It comprises a base web of paper, or the'like, on 'onesurfaceof which, called the transfer surface or rear surface, a coating is applied which becomes a solid pressure-rupturable insulating film in which are entrapped a profuse number of minute liquid droplets in which a color reactant substance has been dissolved. These droplets are, on the average, of the order of from 1 to 5 microns in diameter and are spaced apart, on the average, a distance of the order of /2 micron. The preferred thickness of this coating forming the transfer surface, when, dry, is of the order of .001 of an inch.

The transfer coating is made by dissolving one part, by weight, of animal gelatin, having an isoelectric point of pH 8 and a jelly strength of 275 grams as measured by the Bloom gelometer, with three parts, by weight of water heated to 150 Fahrenheit.

Into four parts, by weight, of gelatin solution there is dispersed, or emulsified, three parts, by weight, of a solution of crystalviolet lactone, which is 3,3 bis(p-dimethylaminophenyl)-6 dimethylamino phthalide, mixed with an equal weight of bis(p-dimethylaminophenyl) methane, being known as methylene base and having the structure The solution of crystal violet lactone and methylene base is made by dissolving 1 parts, by weight, of crystal violet lactone and 1 parts, by weight, of methylene base in 97 parts, by weight, of chlorinated diphenyl which has a chlorine content averaging 48 per cent by weight. This solution is heated to the temperature of the gelatin solution before it is added thereto and emulsified.

The emulsion is applied while still hot, or if allowed to cool, after reheating to 150 Fahrenheit, and is dried either under normal atmospheric conditions or by artificial means such as a hot air blast or on a heated drying drum such as is commonly used in paper coating machines. It is considered that drying under normal atmospheric environment gives a somewhat better water resistance to the dried film or coating in which the chlorinated diphenyl solution droplets are entrapped.

The dried transfer coating is next treated to drive the droplets from the top surface portion of the film into the interior of the film so as, in effect, to form a surface skin thereon. This is accomplished by wetting the surface of the dried film with water at room temperature, that is from 70-80 Fahrenheit, which water has added thereto 1 per cent, by weight, of formaldehyde and 0.1 per cent, by weight, of a wetting agent such as dioctyl ester of sodium sulfosuccinate. The wetting should be allowed to persist for several minutes followed by a drying operation in a low humidity atmosphere, either at room temperature or at an elevated temperature as high as 180 Fahrenheit. The surface wetting may be accomplished by floating the coated paper on the water, coated side down, or by carrying it around a partially submerged drum with the coated surface facing outwardly.

Onto the front receiving surface of the sheet is coated the adsorbent color reactant material in a binder. In making the adsorbent coating, 20 per cent, by weight, of paper coating starch in water is cooked at 200 Fahrenheit for minutes and cooled to room temperature. Separately, 1 part by weight of attapulgite, that is to say Attapulgus clay, is dispersed in three parts, by weight, of water, by use of a ball mill or equivalent. 1 -"O11:1 parts, by weight, of the attapulgite dispersion is mixed with one part, by weight, of the starch solution. The resultant mixture is applied to the sheet, at room tem-- perature, in any convenient manner, as by a paper coating machine. This adsorbent coating,

when dry, should have a thickness of about .0005 of an inch.

Thecoating thickness specified may be varied by 25 per cent, or more, without interfering with the sensitivity thereof.

This record material, in the unused state is substantially white on both sides and the droplets of color reactant when expressedby pressure onto the absorbent surface of another like sheet will produce a dark blue mark, which intensifies on standing, defining sharply the area of applied pressure. The droplet size is so small that the mark appearing on the adsorbent surface caused by drawing a line on an overlying sheet appears as a continuous line, and not as a series of dots. lhe needle-like structure of attapulgite prevents any effective masking of it by the starch binder.

- The compound crystal violet lactone may be made by the process described in United States Letters Patent No. 2,417,897, issued March 25, 1947, on the application of Clyde S. Adams, although the compound is incorrectly named in that patent as 3,3 bis(p-dimethylaminophenyl) B-dimethylaminophenyl phthalide. An application for reissue of that patent to correct the name is now pending.

Example 2'.Another embodiment of the invention is in the substitution of 1 /2 parts by weight of crystal violet lactone for the methylene base of Example 1, making 3 parts, by weight, of crystal violet lactone. The color produced is the same as in Example 1.

- Example 3.Another embodiment of the invention is the use of malachite green lactone, which is 3,3 bis(p-dimethylaminophenyl) phthalide instead of the crystal violet lactone of Example 2. This provides a substantially white record material giving a green color when adsorbed on attapulgite but it is not as intense as the blue of crystal violet lactone.

Example 4.Another embodiment of the invention is the use of an equal weight of tetrachloro malachite green lactone, that is to say 3,3 bis(p dimethylaminophenyl) 4,5,6,7- tetrachloro phthalide, in place of the crystal violet lactone of Example 2. This provides a substantially white record material giving a green color reaction. 1

Example 5.-Another embodiment of the invention is the use of an equal weight of 3,3 bis(p diethylaminophenyl) 6 dimethylamino phthalide, in place of the crystal violet yellow but capable of giving a blue-gray mark to the receiving surface of an under sheet.

In Examples-2 to 5, inclusive, the attapulgite can be replaced by the zeolite materials mentioned as adsorbents, or by attapulgite in which the natural base exchange cations have been replaced by the described substitute cations, or by halloysite or magnesium trisilicate.

In Examples 1 to 6, inclusive, there may be substituted for the starch a mixture of starch, casein and a synthetic latex made of butadienestyrene copolymer material. In such a binder when dried with the adsorbent particles therein,

the amount of starch should be 7 per cent, the amount of casein should be 1 per cent and the amount of latex should be 7 per cent, all by weight, with respect to the weight of the adsorbent material. 7, V p

In making the binder containing casein and latex, a starch solution, as described in Example 1, is made and allowed to cool. Next, 1 part of casein is dispersed in two parts of cold water, by weight, and allowed to swell for one-half hour, after which seven more parts, by weight, of cold water and /10 of a part, by weight, of ammonium hydroxide of Beaum are added. This casein dispersion is heated on a Water bath at 165 Fahrenheit for 15 minutes and then allowed to cool. The latex to be used should contain approximately per centof solids in water. The adsorbent material particles to beused are dis-- persed in water asset out in Example 1 except the water should contain 0.2 per cent, by weight,

of sodium pyrophosphate. To 10 parts, by weight, of the dispersed adsorbent, eliminating the weight. of the water, is added 3.5 parts, by weight, of the starch solution, 1.6 parts, by weight, of the latex, and 1 part, by weight, of the casein solution. This binder material is characterized by greater adhesion to the paper and has excellent properties as far as the access of the adsorbent particles to the action of the liquid color reactant droplets expelled thereonto is concerned.

Referring to the drawing, H3 indicates the sensitized receiving surface coating containing the adsorbent color reactant, ll indicates the supporting web, such as paper, and 12 indicates the transfer coating containing the liquid droplets in which the adsorbate color-reactant material is dissolved.

A particular system utilizing the novel manifold record material disclosed herein is disclosed in our co-pending application for U. S. Letters Patent, Serial No. 41,757, filed July 31, 1948, wherein a stack of such sheets in superimposed relation is provided for use in making multiple copies through a single impression.

It is understood that the novel manifold rec- 0rd material described herein is susceptible of considerable variations without departing from the spirit of the invention.

What is claimed is:

1. A sensitized record material adapted to be used in conjunction with other record material of the same kind, in superimposed relation and faced in the same direction, to form a manifold pack, including a sheet of material suitable for a manifold record material base web, said sheet having a front receiving surface and a rear transfer surface; a coating on the front receiving surface of the sheet comprising a binder containing profuse numbers of minute solid particles of an inorganic adsorbent material; and a pressurerupturable coating on the rear transfer surface, having entrapped therein a profuse number of minute liquid droplets containing an organic substance which is adsorbable on material like the adsorbent coating causing rupture of the coating receiving surface and reactant therewith on contact to form a distinctive color, recording pressures on the front receiving surface through the adsorbent coatingcausingv rupture of, the coating on the rear transfer surface locally at the points of pressure there to release and extrude on the surface of the said ruptured coating droplets of the liquid, there available for adsorption on the receiving surface of an under sheet to produce a distinctively colored mark thereon, the organic reactant substance being an aromatic compound having a double bond system which is convertible to a more highly polarized conjugated form upon;

taking part in an electron acceptor-donor surface, chemical reaction, giving it a distinctive color, and the inorganic adsorbent reactant being. an. acid relative to the organic reactant so as to be an electron acceptor when in adsorption contact with the organic adsorbate.

2. The record material of claim 1 in which the sheet of material forming the base web is paper.

3. The record material of claim 1 in which the liquid droplets have dissolved therein the adsorbate material.

4. The record material of claim 1 in which the liquid droplets consist of a liquid oily, nonevaporable substance in which the adsorbate substance is dissolved and which is inert and acts only as a vehicle for the adsorbate in the formation of color on adsorbent material on an underlying sheet.

5. The record material of claim. 1 in which. the adsorbent material is attapulgite.

6. The, record material of claim 1 in which the adsorbate material is crystal violet lactone, which is 3,3 bis(p-dimethylaminophenyl) -6-dimethylamino phthalide, having. the structure (CHa)2N a)2.

mixed with methylene base, which is bis .pdimethylamino-phenyl) methane which has the structure UN (C392 OLD 8. The record material of claimv 1 in which; the adsorbate material is malachite green lactone,

which is 3,3 bis(p-dimethylaminophenyl) phthalide, havingthe structure (CHahN- -N( Ha):

9. The record material of claim 1 in which the adsorbate material is tetrachloro malachite green lactone,- which is 3,3 bis(p-dimethylaminophenyl) 4,5,6,7 tetrachloro phthalide, having the structure 10. The record material of claim 1 in which the adsorbate material is 3,3 bis(p-diethylaminophenyl)-6-dimethylamino phthalide, having the structure 11. The record material of claim 1 in which the adsorbate material is 2,4 bis[p- (p-dimethylaminophenylazo) anilinol-fi-hydroxy sym. triazine, having the structure 12. The record material of claim 1 in which the liquid in which the adsorbate substance is contained is a chlorinated diphenyl.

13. The record material of claim 12 in which the chlorinated diphenyl has a chlorine content of about 48 per cent, by weight.

14. The record material of claim 1 in which the steps of coatingone side ofa sheet of material, suitable for a manifold web,'with a film of binder material in which is profusely dispersed minute solid particles of an inorganic adsorbent material which is one of two substances which comprise an inorganic adsorbent and an organic adsorbate which produce color in contact; and the step of coating the other side of the sheet with an emulsion having a continuous phase dryable to a pressure-rupturable film and having a discontinuous phase'of an inert oily liquid containing the adsorbate substance whereby upon drying the discontinuous phase is entrappedin the film as a profusion of minute droplets of liquid which may be released locally by pressure applied to' the sheet, the organic adsorbate being an aromatic compound having a double bond system which is convertible to a more highly polarized conjugated form upon taking part in an electron acceptordonor surface chemical reaction, giving it a distinctive color, and the inorganic adsorbent being an acid relative to the organic adsorbate so as to SM N(OH' 21. The process of claim '16 wherein the adsorbate material is 3,3 bis(p-dimethylaminophenyl) 4,5,6,7 tetrachloro phthalide, having the structure ahNQ mom), 0

22. The process of claim 16 in which the adsorbate material is 3,3 bis(p-diethylaminophenyl) phthalide, having the structure 23. The process of claim 16 in which the adsorbate material is 2,4 bis[p-(p-dimethylaminophenylazo) anilinol-G-hydroxy sym. triazine, having the structure N H H0(|3% o-nOrhNO-mom),

K i o 24. The process of claim 16 in which the oily liquid is chlorinated diphenyl.

25. A sensitized record material sheet for use in a manifold stack of similar sheets wherein an impression made on the top sheet causes a distinctively colored like impression on each under sheet in the stack including, in combination, a base sheet; a coating on the front surface of the sheet containing particles of an adsorbent material; and a pressure-rupturable coating on the rear surface of the sheet containing droplets released by rupture of the coating, said droplets containing an adsorbate substance color-reactant 25 on adsorption contact with particles like those so as to be an electron acceptor when in adsorp- 35 tion contact with the organic compound.

26. The process of claim 16 in which adsorbate material is crystal violet lactone, which is 3,3 bis(p-dimethylaminophenyl) 6 dimethylamino phthalide, having the structure 27. The process of claim 26 in which the crystal violet lactone is partially replaced by methylene 15 base, which is bis(p-dimethylaminophenyl) methane, having the structure The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,781,902 Gill Nov. 18, 1930 2,168,098 Groak Aug. 1, 1939 2,299,693 Green Oct. 20, 1942 2,299,694 Green Oct. 20, 1942 2,374,862 Green May 1, 1945 OTHER REFERENCES Hauser et al.: Color Reaction Between Clays and Amines, July 1940, pp. 1811-14. 

